This is Part 4 of a series covering the restoration of an eBay purchased 240SX Convertible. If you missed Part 3 you can find it here:

Welcome back to another installment of “Guy on the internet complains about his crappy car”...I mean, The eBay 240SX Convertible. After reading through the first 3 parts of this blog, you my dear readers, are probably slightly depressed and expecting Part 4 to be more of the same. Have no fear, this car does have its positives and today is your lucky day. Part 4 is about the modifications and changes I have made to make the car my own.

The Used Car Interior

In the downtime sourcing parts for the surgery covered in Part 2 of this blog, I decided to take some time and make a list of the interior items that I wanted to refresh. The car was lacking a radio, the stock seats were very stained and had little to no foam left, and although I had a dashboard without cracks (an impressive rarity in the 240SX world), mine did have one hell of a scrape in it. I’m a mildly OCD person so it bugged me, rather strongly in fact. Finally, although the stock analog gauges were perfectly serviceable, I had been introduced to the optional Digital gauges and Heads Up Display (HUD) in my coupe project. I wanted this car to scream ‘90s, and nothing says ‘90s tech like digital dashboards.

A few of the items on my “Unhappy List” were difficult enough to fix as to be essentially impossible, due mainly to parts being long out of production. Things like the door panels, some buggered up weather stripping, and the tonneau cover and its “ziploc strip” mounting rail. The difficulty with fixing these items is because they were specially made for the convertible by American Sunroof Company, the people who did the convertible...ahem...conversion.


Tear It All Out

Once I had my list of items to fix in the car, I made my trip to Elite JDM in Philadelphia PA for the spare frame section. While I was down in the impressive warehouse of JDM parts run by Nick, I asked him about the availability of some of the parts I needed. Although he did not have any of the convertible specific parts, he did have a set of fairly low mileage seats for my car. In a tiger stripe pattern, grey, mouse-fur material no less. Although my interior was stock and the seats would not totally match, the mouse-fur seemed like a more comfortable material than the tweed that infected every fabric surface in the car originally. The fact that they also had good foam with lots of life left in them was another mark in the win column.

Returning home with my score from Philly, it was time to pull the seats out of the car and do some intensive cleaning. A carpet shampooer was rented for this job and the tear down began. I must admit that interior work is nice in a convertible. I still have nightmares about removing the stock seats from my Ford Focus and the geometry lessons needed to get them out of a door opening. With the top down on the 240, it was as easy as unbolting 4 bolts, disconnecting a wire for the seatbelt light, and passing the whole assembly up and over the side of the car.


Easy access.

With the seats out, I vacuumed the years or accumulated crud from the carpet and then proceeded to shampoo the carpets twice. Soon, years of dirt, grease, and other unmentionables were lifted and exorcised from the carpet. I also removed a fair amount of glass, just a further indication of how bad the previous accident was. I allowed the inter to dry overnight and then installed my new seats. It may not have had a radio, but at least it was comfy to sit in.

Too much ass is sometimes a bad thing.


Much nicer...

Undercover Work

After finishing the light cleaning on the interior, I got hard to work on the frame surgery. Cutting, measuring, and drilling became a nightly obsession, and I would routinely send progress updates to my girlfriend when I was done. We would talk about trips we were going to take in the car and I would mention that I was always on the lookout for a factory tonneau cover. For those who do not speak car, the tonneau cover aka the convertible top boot, is a cover that was made to protect the top of the car from the sun and dirt when you have the top down.


Unfortunately, the items are rather large, ungainly, and take up a lot of the minuscule trunk space on these cars. This invariably leads to them being left in the garage, forgotten about, and then the cars selling on without them. Finding one is not cheap, usually with one or two popping up on eBay every now and then. Prices are variable but usually more than $200 for one in Ok condition.

One day while at work, I received a text from my significant other that a package was arriving at my house that day. Returning home that evening I saw the most astoundingly odd package I have ever experienced.

Wrap with whatever you have.


Upon opening what I would loosely term a “box”. I was greeted with a gift that my girlfriend had bought for me. Apparently she was perusing eBay while I was working on the frame and had managed to track down a tonneau cover for the car, in excellent condition and with the original storage bag no less! There is a reason she is now my wife...

240SX Tonneau Cover

The tonneau cover is held onto the car by 1) slipping the back edge under the trim at the base of the convertible top (Near the trunk lid), 2) a set of snaps by the seat belt pillars, and 3) a “ziplock strip” behind the rear seats. My car had only two of these fastening points as the ziploc strip long ago perished and been discarded. While the car looked amazing with the tonneau cover on and it was reasonably secure around town, I was always afraid to drive at highway speeds, lest the expensive gift from my significant other go flying off and be run over by a truck. For many years I used the tonneau around town and stowed it whenever I would be on the highway.


After the 4 year downtime (See Part 3), a co-worker of mine (coincidentally, the one I mentioned in Part 2 who provided spot weld cutters) had just purchased a 3D printer for home use. Seizing on his generous offer to “print anything [you] may need” I called ASC and requested the original production documents for the ziploc strip. I was promptly sent a drawing lacking any dimensions with a note attached wishing me “good luck”. Not to be deterred, I put a request for photos and measurements out on the NICO (Nissan Infiniti Club of Owners) forum and soon had the information I needed.

I whipped up an initial version in CAD software based off of the original design used by ASC, and sent it to my coworker. The next morning he arrived with a printed part which I tested at lunch time. It barely locked into the tonneau and did not stay in place on the original car mounting point. Thus a Rev B was created to address these issues while maintains the original geometry from the ASC print and 24 hours later, it too failed to work properly. Although my design changes helped it attach to the tonneau better, it still refused to stay mounted to the car. A third version was worked up, using an entirely new geometry, ignoring the ASC design. Feeling fairly confident, I requested 2 examples of Rev C to be produced. The next day at lunch I put them on the car and declared them a success. This lead to an impromptu high speed test on the way home that night as I had to pass 80mph in order to get around a semi truck with a failing tire. The tonneau held on spectacularly with the 2 clips.

Test items (the two white parts)


Satisfied with the design, I lobbied my supervisor to allow me to produce 5 more of the parts as calibration artifacts for the 3D printer I had purchased for our prototype shop. Given the size of the items, they functioned well in testing multiple parameters of the printer, from part warping to layer adhesion, and even flatness of the print surface. I gained a full set of clips in black and the company gained proof that the 3D printer was functioning correctly and would serve us well.

All 5 production parts (looking through rear window)

Some of that Good Ol’ 90's Tech

Pleased with the progress of the car at this point and enjoying the top down cruising it offered, I decided to tackle the last major interior complaint I had. No, not the radio. That’s such a major job that I would have to re-wire most of the cabin. That can wait. I’m not that daring...


No, the issue I wanted to tackle was the damaged dashboard and the plain and boring analog gauges. The 240SX came from the factory with a few things that really made it stand out in the 90's. Certain trims came with a 4 wheel steering system called HICAS (HIgh Capacity All wheel Steering), some trims came with Anti-lock brakes, and some trims, like my previous Coupe project, came with a digital dashboard and a Heads Up Display (HUD). The convertible was offered with none of these, in fact the only options were A/C (that everyone bought) and a CD player (that no one bought). I had however, kept the dashboard, gauges, and HUD unit from my coupe when I sold it and knowing it did nothing in storage, resolved to equip my convertible with them. When you start building 240's you end up becoming a pack rat. You never know what will fail so you keep spares of everything, and spares for the spares, and spares of the spares of the spares, and...well you get the point.

Factory Analog Gauges -Japanese Market (Photo Credit: Elite|JDM)

With a toddler in the house and my wife expecting our second child, I did not have a lot of time available to remove a dashboard and do gauges no matter how desperately I wanted to. Thankfully my bother-in-law and his girlfriend decided to visit us and managed to entertain everyone enough that I could spend a weekend on my project. In order to get the gauges to work properly however I had to tackle 3 problems. 1) The HUD equipped cars have a different dashboard to allow the HUD to mount. 2) The digital gauges use a different stub harness to connect the gauges to the main car wiring. 3) HUD cars had a silvered section on the windshield for the HUD to reflect off of.


Two of these would not be an issue as I had the HUD dashboard from my coupe, and the gauges I took from that car still had the stub harness on them as well. Deciding I would tackle the silvered section last, I proceeded to remove my old dashboard. While proceeding with the removal, a few items started to fall out from behind the dash. Most of it was the usual dirt and detritus, but there was also glass. Lots and lots of broken glass. I guess that crash was a little worse than I had thought.

Now you understand why padded dashes are a thing...

One Saturday, one Sunday morning, and one very annoyed wife later, I had the new gauges in the car. In the garage with the door closed, the gauges and HUD worked perfectly. The display from the HUD reflected off the interior surface of the windshield. Unfortunately, going outside in the sun and putting on polarized glasses completely wiped out the HUD. That Monday morning I placed a call to a local auto glass tint shop, and soon I had a roll of scrap limo tint to play with. I measured the area where the HUD reflects on the windshield, and drew up a squircle (a square with radiused edges) in CAD to cover that area. Attaching a sharpie pen to our CNC mill at work, handwriting a short G-Code program, and I soon had a nice outline on my tint to follow. After cutting out the squircle and applying it to the inside of the windshield, I finally had my HUD and digital dash. As far as I know, I may have the only convertible with the digital dash and HUD.


Party like its 1989.


While this section is almost unnecessarily long, it does cover most of the work I have done to adapt this car to my tastes. With this, the end of Part 4, we have covered the purchase of the car, the major frame repairs, the electrical gremlins, and my personal touches. As of now the car is fairly reliable and can be concidered “working”.


So what does that mean then? Does is mean that the car is now done? No. Does this cover EVERYTHING that I have done to the car? No. Does the blog end here? Probably not. Knowing this car and having an idea of future plans I am fairly sure you will be hearing from me again. After all, some major plans are afoot for this little eBay basket case. Where they end up, no one can say. But of this I can assure you, my loyal readers, it will be documented here.